Ab initio optical properties of Si(100)

We compute the linear optical properties of different reconstructions of the clean and hydrogenated Si(100) surface within DFT-LDA, using norm-conserving pseudopotentials. The equilibrium atomic geometries of the surfaces, determined from self-consistent total energy calculations within the Car-Parrinello scheme, strongly influence Reflectance Anisotropy Spectra (RAS), showing differences between the p(2x2) and c(4x2)reconstructions. The Differential Reflectivity spectrum for the c(4x2) reconstruction shows a positive peak at energies < 1 eV, in agreement with experimental results.Comment: fig. 2 correcte

Developing a new Bayesian Risk Index for risk evaluation of soil contamination

Supplementary data associated with this article can befound in the online version, at http://dx.doi.org/10.1016/j.scitotenv.2017.06.068. These data include the Google map of the most important areas described in this article.Industrial and agricultural activities heavily constrain soil quality. Potentially Toxic Elements (PTEs) are a threat to public health and the environment alike. In this regard, the identification of areas that require remediation is crucial. In the herein research a geochemical dataset (230 samples) comprising 14 elements (Cu, Pb, Zn, Ag, Ni, Mn, Fe, As, Cd, V, Cr, Ti, Al and S) was gathered throughout eight different zones distinguished by their main activity, namely, recreational, agriculture/livestock and heavy industry in the Avilés Estuary (North of Spain). Then a stratified systematic sampling method was used at short, medium, and long distances from each zone to obtain a representative picture of the total variability of the selected attributes. The information was then combined in four risk classes (Low, Moderate, High, Remediation) following reference values from several sediment quality guidelines (SQGs). A Bayesian analysis, inferred for each zone, allowed the characterization of PTEs correlations, the unsupervised learning network technique proving to be the best fit. Based on the Bayesian network structure obtained, Pb, As and Mn were selected as key contamination parameters. For these 3 elements, the conditional probability obtained was allocated to each observed point, and a simple, direct index (Bayesian Risk Index-BRI) was constructed as a linear rating of the pre-defined risk classes weighted by the previously obtained probability. Finally, the BRI underwent geostatistical modeling. One hundred Sequential Gaussian Simulations (SGS) were computed. The Mean Image and the Standard Deviation maps were obtained, allowing the definition of High/Low risk clusters (Local G clustering) and the computation of spatial uncertainty. High-risk clusters are mainly distributed within the area with the highest altitude (agriculture/livestock) showing an associated low spatial uncertainty, clearly indicating the need for remediation. Atmospheric emissions, mainly derived from the metallurgical industry, contribute to soil contamination by PTEs.Carlos Sierra obtained a grant from the “Severo Ochoa (BP10-112)” Programme(Ficyt, Asturias,Spain).info:eu-repo/semantics/publishedVersio

Love and Borders

There are many examples of optimization problems whose associated polyhedra can be described much nicer, and with way less inequalities, by projections of higher dimensional polyhedra than this would be possible in the original space. However, currently not many general tools to construct such extended formulations are available. In this paper, we develop a framework of polyhedral relations that generalizes inductive constructions of extended formulations via projections, and we particularly elaborate on the special case of reflection relations. The latter ones provide polynomial size extended formulations for several polytopes that can be constructed as convex hulls of the unions of (exponentially) many copies of an input polytope obtained via sequences of reflections at hyperplanes. We demonstrate the use of the framework by deriving small extended formulations for the G-permutahedra of all finite reflection groups G (generalizing both Goeman's extended formulation of the permutahedron of size O(n log n) and Ben-Tal and Nemirovski's extended formulation with O(k) inequalities for the regular 2^k-gon) and for Huffman-polytopes (the convex hulls of the weight-vectors of Huffman codes)

Sellar region atypical teratoid/rhabdoid tumors in adults: Clinicopathological characterization of five cases and review of the literature

Atypical teratoid/rhabdoid tumors (AT/RTs) are highly malignant CNS neoplasms that typically occur in children &lt;2 years of age. These are characterized by high-grade histologic features and mutations of the INI1/SMARCB1 gene readily detected by loss of expression by immunohistochemistry. Among adults, the majority of AT/ RTs occurs in the cerebral hemispheres. A small number of adult AT/RTs involving the sellar and suprasellar region reported in the literature suggest a distinct clinical course for this group. Here, we describe detailed clinical and genetic characterization of 5 adult patients with AT/RTs involving the sellar and suprasellar region, and provide a review of the available clinical and genetic features of 22 previously reported cases in order to help increase our understanding of this unusual entity

Molecular profiling of long-term IDH-wildtype glioblastoma survivors

Background: Glioblastoma (GBM) represents an aggressive cancer type with a median survival of only 14 months. With fewer than 5% of patients surviving 5 years, comprehensive profiling of these rare patients could elucidate prognostic biomarkers that may confer better patient outcomes. We utilized multiple molecular approaches to characterize the largest patient cohort of isocitrate dehydrogenase (IDH)-wildtype GBM long-term survivors (LTS) to date. Methods: Retrospective analysis was performed on 49 archived formalin-fixed paraffin embedded tumor specimens from patients diagnosed with GBM at the Mayo Clinic between December 1995 and September 2013. These patient samples were subdivided into 2 groups based on survival (12 LTS, 37 short-term survivors [STS]) and subsequently examined by mutation sequencing, copy number analysis, methylation profiling, and gene expression. Results: Of the 49 patients analyzed in this study, LTS were younger at diagnosis (P = 0.016), more likely to be female (P = 0.048), and MGMT promoter methylated (UniD, P = 0.01). IDH-wildtype STS and LTS demonstrated classic GBM mutations and copy number changes. Pathway analysis of differentially expressed genes showed LTS enrichment for sphingomyelin metabolism, which has been linked to decreased GBM growth, invasion, and angiogenesis. STS were enriched for DNA repair and cell cycle control networks. Conclusions: While our findings largely report remarkable similarity between these LTS and more typical STS, unique attributes were observed in regard to altered gene expression and pathway enrichment. These attributes may be valuable prognostic markers and are worth further examination. Importantly, this study also underscores the limitations of existing biomarkers and classification methods in predicting patient prognosis

Absence of Direct Delivery for Single Transmembrane Apical Proteins or Their “Secretory” Forms in Polarized Hepatic Cells

The absence of a direct route to the apical plasma membrane (PM) for single transmembrane domain (TMD) proteins in polarized hepatic cells has been inferred but never directly demonstrated. The genes encoding three pairs of apical PM proteins, whose extracellular domains are targeted exclusively to the apical milieu in Madin-Darby canine kidney cells, were packaged into recombinant adenovirus and delivered to WIF-B cells in vitro and liver hepatocytes in vivo. By immunofluorescence and pulse-chase metabolic labeling, we found that the soluble constructs were overwhelmingly secreted into the basolateral milieu, which in vivo is the blood and in vitro is the culture medium. The full-length proteins were first delivered to the basolateral surface but then concentrated in the apical PM. Our results imply that hepatic cells lack trans-Golgi network (TGN)-based machinery for directly sorting single transmembrane domain apical proteins and raise interesting questions about current models of PM protein sorting in polarized and nonpolarized cells